Windmills and wind turbine machines of various designs have been previously proposed for use in converting wind energy to electrical energy. Machines of the type utilizing a plurality of exposed blades rotating about a horizontal axis are in commercial use in a number of different locations. However, such machines cannot be safely operated in high wind conditions because they lack sufficient structural integrity. Furthermore, such machines are deadly to any birds which may fly into the path of the rotating blades.
Previously disclosed wind turbines typically utilize a rotor which is rotatable about a vertical axis. The rotor normally includes a plurality of blades. A plurality of stationary wind deflectors or wind-directing blades are positioned around the rotor to deflect air toward the rotor blades. The typical wind deflectors are generally planar or slightly curved devices which are vertically oriented and are positioned around the perimeter of the rotor.
A variation of the typical wind turbine apparatus previously known is described in U.S. Pat. No. 5,391,926. That apparatus requires the use of passive stationary blades which have corresponding and opposing double curves. The apparatus as shown in the patent also utilizes twice as many stationary blades as rotor blades. The opposing double curves of the stationary blades leads to undesirable air turbulence, thereby inherently limiting the efficiency of the apparatus.
There has not heretofore been provided a wind turbine apparatus having the features and advantages provided by the present invention.